The present invention relates to a power generation system and method, and especially relates to a hybrid electric powertrain having an engine configured to produce reformate to feed a solid oxide fuel cell.
Alternative transportation fuels have been represented as enablers to reduce toxic emissions in comparison to those generated by conventional fuels. At the same time, tighter emission standards and significant innovation in catalyst formulations and engine controls has led to dramatic improvements in the low emission performance and robustness of gasoline and diesel engine systems. This has certainly reduced the environmental differential between optimized conventional and alternative fuel vehicle systems. However, many technical challenges remain to make the conventionally fueled internal combustion engine a nearly zero emission system having the efficiency necessary to make the vehicle commercially viable.
Alternative fuels cover a wide spectrum of potential environmental benefits, ranging from incremental toxic and CO2 emission improvements (reformulated gasoline, alcohols, LPG, etc.) and to significant toxic and CO2 emission improvements (natural gas, DME, etc.). Hydrogen is clearly the ultimate environmental fuel, with potential as a nearly emission free internal combustion engine fuel (including CO2 if it comes from a non-fossil source). Unfortunately, the market-based economics of alternative fuels or new power train systems are uncertain in the short to mid-term.
The automotive industry has made very significant progress in reducing automotive emissions for both the mandated test procedures and the xe2x80x9creal worldxe2x80x9d. This has resulted in some added cost and complexity of engine management systems, yet those costs are offset by other advantages of computer controls: increased power density, fuel efficiency, drivability, reliability and real-time diagnostics.
Future initiatives to require zero emission vehicles appear to be taking us into a new regulatory paradigm where asymptotically smaller environmental benefits come at a very large incremental cost. Yet, even an xe2x80x9cultra low emissionxe2x80x9d certified vehicle can emit high emissions in limited extreme ambient and operating conditions or with failed or degraded components.
What is needed in the art is a power generation system having essentially zero emissions, high efficiency, and compatibility with existing fuels and infrastructure.
The present system and method relate to an engine configured and operated to produce a hydrogen rich engine exhaust and to oxygen enrichment devices to further optimize production of hydrogen rich engine exhaust. The present hydrogen rich exhaust engines include a free piston gas generator with rich homogenous charge compression ignition, an oxygen generator and rich internal combustion engine cylinder system, and a rich inlet turbo-generator system with exhaust heat recovery. Oxygen enrichment devices include pressure swing absorption (PSA) with oxygen selective materials, oxygen separators such as an SOFC oxygen separator and an oxygen separator utilizing a ceramic membrane and differential pressure to drive oxygen across the membrane.
The present invention further relates to a power generation system and method employing the present hydrogen rich exhaust engines and oxygen enrichment devices, and especially relates to a hybrid electric powertrain having an engine configured to produce reformate to feed a solid oxide fuel cell. The power generation system comprises an engine having an intake and an exhaust, wherein said engine is configured to produce a hydrogen rich engine exhaust; an air supply in fluid communication with said engine intake; a fuel supply in fluid communication with said engine intake; at least one SOFC having an air intake in fluid communication with an air supply, a fuel intake in fluid communication with said engine exhaust, a SOFC effluent and an air effluent.
The method comprises supplying at least a first portion of fuel and a first portion of air to an engine, wherein said engine is configured to produce a rich engine exhaust; reacting said first portion of fuel and said first portion of air in said engine to produce a hydrogen rich engine exhaust; introducing said hydrogen rich engine exhaust to a fuel intake of a SOFC; introducing a second portion of air to an air intake of said SOFC; and ionizing oxygen in the second portion of air such that the ionized oxygen migrates to the fuel side of the SOFC where it reacts with said hydrogen rich engine exhaust to produce a SOFC effluent.